Engine block heaters are common accessories used on internal combustion engines in cold climates. Engine block heaters aid in warming engine blocks when the engines are not in operation. Among other advantages a warmed engine provides for easier starting, can help to reduce emissions, and aids in warming the passenger compartment where the engine is used in an automobile. Although engine block heaters are commonly used in association with cars and trucks, they may also be used on recreational vehicles, construction equipment, and on most other applications that utilize an internal combustion engine. While there are many different forms, sizes and configurations of engine block heaters (each being designed for particular application on particular engines) all conventional engine block heaters include an electrical heating element that is connected or otherwise secured to the engine block, or a component thereof, and that has attached or attachable to it an electrical cord to supplies electricity to the heating element. Typically, household voltage (which most commonly will be 110 or 220 volts depending on the jurisdiction) is applied to a resistive heating element, causing it to heat up, and in turn causing the element to heat or warm the engine block.
Engine block heaters are generally of two main types; namely, cartridge heaters or immersion heaters. Cartridge heaters have their heating elements sealed within a cylindrical cartridge that is received within a correspondingly shaped bore within the engine block. The cartridges do not come into direct contact with the interior or the operational fluids of the engine. As the cartridge is heated, so is the engine block. Immersion heaters are commonly threaded through a bore in the side of the engine block such that their heating elements are immersed within engine coolant inside the block, much as in the case of an electric heating element used in an electric water heater. As the element is heated it transfers heat to the engine coolant.
Automobile manufacturers are increasingly attempting to better utilize the available space within the engine compartment of a car or truck in order to reduce the overall size of the vehicle and to generally help to increase its operating efficiency. As a result, the amount of open or available space for the installation of accessories such as engine block heaters has been reduced over time. In many instances engine block heaters must be installed in tight quarters, with their cords having to be routed around obstacles, components that may be hot to the point that they could cause damage to the cord if it were to come into contact with them, or around sharp or moving parts that could damage the cord.
In most instances, the engine block heater is comprised of a heating element and a separate, detachable, cord set. The cord sets are manufactured such that they can be separated from the heating element, largely to allow for the replacement of one, or the other, of the cord set and the heating element should one become damaged or malfunction. Installation of such engine block heaters requires that the heating element be attached or otherwise secured to the engine block, after which one end of the cord set is connected to the heating element with the opposite end being routed through the engine compartment to a location that permits it to be connected to a source of electricity. On account of the confined space within which the engine compartment, many cord sets are designed with a 90 degree connector to secure the cord set to the heating element, thereby reducing the overall length of the assembled unit. Unfortunately, current cord sets and heater elements permit the cord to be mounted to the heater in a single orientation, meaning that the cord extends outwardly from the heating element in a single, fixed, direction. With the orientation of the power cord fixed relative to the heating element, an installer is thus limited in terms of his or her ability to easily route the cord set away from obstacles, heated objects within the engine compartment, sharp surfaces and moving parts. To accommodate different installation scenarios, installers are often forced to have on hand an inventory of multiple cord sets having differently oriented electrical connectors for mating with the contacts of the heating element, depending on its final position when installed in the engine.